Barton Willis wrote:
> maxima-bounces at math.utexas.edu wrote on 09/04/2007 12:12:27 PM:
>
>> Stavros Macrakis wrote:
>>> I'd suggest having polyroots take explicit polynomials rather than
>>> coefficient vectors as input.
>>>
>>> -s
>> Yes. Laziness on my part, plus I wasn't exactly sure what the correct
>> way was of getting the coefficients from the polynomial.
>
>
> I think that
>
> (%i4) list_of_poly_coeffs(p,x) := (p : rat(p,x),
> makelist(ratcoef(p,x,k),k,0,hipow(p,x)))$
>
> works OK:
>
> (%i5) list_of_poly_coeffs(prod(x + k,k,1,5),x);
> (%o5) [120,274,225,85,15,1]
>
Thanks, Barton. This works quite nicely, except the coefficients are in
the wrong order. A simple reverse works fine. (Or modifying makelist).
Ray